Nicotiana tabacum, commonly called tobacco, has a huge economic importance worldwide. Among its varieties, Virginia has been chosen in this study. Its average chemical composition includes nicotine (2%), reducing sugars (22%), pectin (6%), fibers (7%), CaO (2%) and K2O (2%), nitrogen (2%). Thermal analysis showed to be an important tool to understand the process of leaf burning. TG/DTG and DTA were the methods applied using Perkin-Elmer and TA Instruments in inert and air atmospheres. Samples of uncased and cased tobacco were analyzed and the results showed loss of water and tobacco volatiles at around 80 degreesC. The main difference between cased and uncased samples lies in the start of oxidation. The production of CO and CO2 began first in the cased unit, suggesting that added sugar may accelerate the reactions. The samples subjected to air atmosphere resulted in less residue, indicating that oxygen interferes with the reactions.